<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  
  <div>
    <button>按钮</button>
  </div>

  <script>

    var btnEl = document.querySelector("button")
    var divEl = document.querySelector("div")

    divEl.onclick = function(event) {
      console.log(this)
      console.log(event.currentTarget)
      console.log(divEl)
      console.log(this === divEl)
    }
    // divEl.addEventListener("click", function() {
    //   console.log(this)
    // })

  </script>

</body>
</html>